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x86/cstate: Allow ACPI C1 FFH MWAIT use on Hygon systems

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Hygon systems support the MONITOR/MWAIT instructions and these can be
used for ACPI C1 in the same way as on AMD and Intel systems.

The BIOS declares a C1 state in _CST to use FFH and CPUID_Fn00000005_EDX
is non-zero on Hygon systems.

Allow ffh_cstate_init() to succeed on Hygon systems to default using FFH
MWAIT instead of HALT for ACPI C1.

Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210528081417.31474-1-puwen@hygon.cn
This commit is contained in:
Pu Wen 2021-05-28 16:14:17 +08:00 committed by Borislav Petkov
parent 2ade8fc650
commit 280b68a3b3
1 changed files with 2 additions and 1 deletions
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3
arch/x86/kernel/acpi/cstate.c
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@ -197,7 +197,8 @@ static int __init ffh_cstate_init(void)
struct cpuinfo_x86 *c = &boot_cpu_data;
if (c->x86_vendor != X86_VENDOR_INTEL &&
c->x86_vendor != X86_VENDOR_AMD)
c->x86_vendor != X86_VENDOR_AMD &&
c->x86_vendor != X86_VENDOR_HYGON)
return -1;
cpu_cstate_entry = alloc_percpu(struct cstate_entry);